Move core ProjectReferenceTargets from Managed-only to Common targets by dfederm · Pull Request #13427 · dotnet/msbuild

dfederm · 2026-03-21T00:14:16Z

Summary

Move the core Build/Clean/Rebuild ProjectReferenceTargets protocol from Microsoft.Managed.After.targets into Microsoft.Common.CurrentVersion.targets so it applies to all project types that import the common targets, not just managed languages (C#, VB, F#). This aligns with the static graph spec which prescribes that common protocols be defined in the common targets.

What changed

Targets files

Microsoft.Common.CurrentVersion.targets: Now contains the core ProjectReferenceTargets for Build, Clean, and Rebuild, including OuterBuild items, SkipNonexistentTargets items, and the extensibility properties (ProjectReferenceTargetsForBuild, etc.)
Microsoft.Common.CrossTargeting.targets: Now contains the cross-targeting outer build protocol (.default dispatch) that was previously inlined in Managed.After.targets
Microsoft.Managed.After.targets: Retains only managed-specific extensions: Publish, DeployOnBuild, GetCopyToPublishDirectoryItems, WPF graph isolation, and InnerBuildProperty/InnerBuildPropertyValues

DeployOnBuild refactor

DeployOnBuild handling changed from property-level composition (appending Publish targets to $(ProjectReferenceTargetsForBuild)) to item-level composition (separate ProjectReferenceTargets items). This is functionally equivalent since the static graph engine merges all items with the same Include value, and eliminates a subtle duplication in the old code where ProjectReferenceTargetsForRebuild included publish targets twice.

Documentation

Updated stale docs.microsoft.com → learn.microsoft.com URL
Converted absolute GitHub links to relative paths
Added prose hints for deep-link references into large targets files
Fixed typo in SkipNonexistentTargets comment

Testing

Unit tests (11 new, all passing)

New file src/Build.UnitTests/Graph/ProjectReferenceTargetsProtocol_Tests.cs covering:

Non-managed project gets core Build/Clean/Rebuild protocol
Managed project protocol unchanged after move
DeployOnBuild property→item migration
Cross-targeting .default dispatch
BuildProjectReferences=false and NoBuild=true fallbacks
Clean/Rebuild propagation through multi-project chains

Manual validation

Tested with old (VS 18 Canary) vs new (bootstrap) MSBuild:

Key result: Non-managed .proj with /graph /isolate — old MSBuild produces MSB4252 isolation violation ("target not specified in ProjectReferenceTargets"), new MSBuild resolves the graph correctly
-getItem:ProjectReferenceTargets /p:IsGraphBuild=true on non-managed .proj: old returns empty, new returns full Build/Clean/Rebuild protocol from Microsoft.Common.CurrentVersion.targets
C++ graph build binlogs produced for manual inspection

Copilot

Pull request overview

Moves the static-graph ProjectReferenceTargets protocol for core Build/Clean/Rebuild from managed-only targets into the common MSBuild targets so it applies to all project types that import the common targets, aligning implementation with the static graph spec.

Changes:

Added core static-graph ProjectReferenceTargets (Build/Clean/Rebuild) to Microsoft.Common.CurrentVersion.targets.
Added cross-targeting (outer build) static-graph ProjectReferenceTargets dispatch protocol to Microsoft.Common.CrossTargeting.targets.
Refactored managed DeployOnBuild propagation from property composition to item-based composition and added new unit tests + doc updates.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Tasks/Microsoft.Managed.After.targets	Removes core Build/Clean/Rebuild protocol and keeps managed-only Publish/DeployOnBuild extensions.
src/Tasks/Microsoft.Common.CurrentVersion.targets	Defines core Build/Clean/Rebuild `ProjectReferenceTargets` protocol for static graph builds.
src/Tasks/Microsoft.Common.CrossTargeting.targets	Defines cross-targeting (outer build) static graph protocol for Build/Clean/Rebuild.
src/Build.UnitTests/Graph/ProjectReferenceTargetsProtocol_Tests.cs	Adds unit tests validating protocol behavior across managed/non-managed and cross-targeting scenarios.
documentation/ProjectReference-Protocol.md	Updates links and clarifies references to protocol/comment locations in targets files.

dfederm · 2026-04-09T20:28:34Z

/azp run

azure-pipelines · 2026-04-09T20:28:42Z

Commenter does not have sufficient privileges for PR 13427 in repo dotnet/msbuild

…of snapshotting protocol XML Addresses Rainer's review comment on PR dotnet#13427. The test now imports Microsoft.Common.targets, Microsoft.Common.CrossTargeting.targets, and Microsoft.Managed.After.targets via $(MSBuildToolsPath) rather than carrying copy-pasted snapshots of their ProjectReferenceTargets sections. Future drift between the graph evaluator and the real protocol will now fire these tests directly instead of leaving them silently stale. Cross-targeting tests pass a NuGetRestoreTargets stub path because Microsoft.Common.CrossTargeting.targets imports $(NuGetRestoreTargets)`nunconditionally (no Exists() guard, unlike Common.CurrentVersion.targets). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Move the core Build/Clean/Rebuild ProjectReferenceTargets protocol from Microsoft.Managed.After.targets into Microsoft.Common.CurrentVersion.targets so it applies to all project types that import the common targets, not just managed languages (C#, VB, F#). This aligns with the static graph spec which prescribes that common protocols be defined in the common targets. Extract the cross-targeting outer build protocol (using .default dispatch) into Microsoft.Common.CrossTargeting.targets where it naturally belongs alongside the DispatchToInnerBuilds target. Refactor DeployOnBuild handling from property-level composition (appending Publish targets to the ProjectReferenceTargetsForBuild property) to item-level composition (separate ProjectReferenceTargets items). This is functionally equivalent since the static graph engine merges all items with the same Include value, and eliminates a subtle duplication in the old code. Microsoft.Managed.After.targets retains managed-specific extensions: Publish, DeployOnBuild, GetCopyToPublishDirectoryItems, WPF graph isolation, and the InnerBuildProperty/InnerBuildPropertyValues definitions. Also fixes: - Update docs.microsoft.com URL to learn.microsoft.com - Convert absolute GitHub links to relative paths in protocol docs - Add prose hints for deep-link references into large targets files - Fix typo: GetTargetFrameworksWithPlatformForSingleTargetFrameworks (plural) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Fix 'managed languaged' typo in Microsoft.Managed.After.targets - Make _env field readonly in ProjectReferenceTargetsProtocolTests - Add clarifying comment explaining why outer build includes both protocols Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Rainer Sigwald <raines@microsoft.com>

Add ProjectReferenceTargetsForBuildInOuterBuild and ProjectReferenceTargetsForCleanInOuterBuild items to Microsoft.Common.CrossTargeting.targets to preserve the extensibility points that were previously available in outer builds via Microsoft.Managed.After.targets. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…of snapshotting protocol XML Addresses Rainer's review comment on PR dotnet#13427. The test now imports Microsoft.Common.targets, Microsoft.Common.CrossTargeting.targets, and Microsoft.Managed.After.targets via $(MSBuildToolsPath) rather than carrying copy-pasted snapshots of their ProjectReferenceTargets sections. Future drift between the graph evaluator and the real protocol will now fire these tests directly instead of leaving them silently stale. Cross-targeting tests pass a NuGetRestoreTargets stub path because Microsoft.Common.CrossTargeting.targets imports $(NuGetRestoreTargets)`nunconditionally (no Exists() guard, unlike Common.CurrentVersion.targets). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

dfederm · 2026-05-23T00:20:29Z

Note: This PR may be blocked until #13855 is merged. Some internal large repos have worked around this issue already by including their own <ProjectReferenceTarget> items and the duplication causes a geometric explosion in large graphs which #13855 fixes.

Copilot AI review requested due to automatic review settings March 21, 2026 00:14

Copilot started reviewing on behalf of dfederm March 21, 2026 00:14 View session

Copilot AI reviewed Mar 21, 2026

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Comment thread src/Tasks/Microsoft.Managed.After.targets Outdated

Comment thread src/Build.UnitTests/Graph/ProjectReferenceTargetsProtocol_Tests.cs Outdated

Comment thread src/Build.UnitTests/Graph/ProjectReferenceTargetsProtocol_Tests.cs Outdated

AR-May assigned SimaTian Mar 24, 2026

dfederm requested a review from a team as a code owner April 9, 2026 18:51

dfederm force-pushed the projref-targets-fixes branch from 3dd7d04 to 57fbc44 Compare April 9, 2026 18:56

rainersigwald reviewed Apr 22, 2026

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Comment thread documentation/ProjectReference-Protocol.md Outdated

Comment thread src/Tasks/Microsoft.Common.CurrentVersion.targets

rainersigwald approved these changes May 12, 2026

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Comment thread src/Build.UnitTests/Graph/ProjectReferenceTargetsProtocol_Tests.cs Outdated

dfederm force-pushed the projref-targets-fixes branch from 062f8fd to 8ca1587 Compare May 13, 2026 16:21

dfederm mentioned this pull request May 13, 2026

Guard NuGetRestoreTargets import in Microsoft.Common.CrossTargeting.targets #13764

Closed

dfederm and others added 6 commits May 21, 2026 14:48

Update documentation/ProjectReference-Protocol.md

14afac4

Co-authored-by: Rainer Sigwald <raines@microsoft.com>

remove XUnit.Abstractions (no longer needed)

b76c0c9

dfederm force-pushed the projref-targets-fixes branch from 8ca1587 to bab1fb4 Compare May 21, 2026 21:48

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Move core ProjectReferenceTargets from Managed-only to Common targets#13427

Move core ProjectReferenceTargets from Managed-only to Common targets#13427
dfederm wants to merge 6 commits into
dotnet:mainfrom
dfederm:projref-targets-fixes

dfederm commented Mar 21, 2026 •

edited by akoeplinger

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dfederm commented Mar 21, 2026 • edited by akoeplinger Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

What changed

Targets files

DeployOnBuild refactor

Documentation

Testing

Unit tests (11 new, all passing)

Manual validation

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Pull request overview

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dfederm commented Apr 9, 2026

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dfederm commented Mar 21, 2026 •

edited by akoeplinger

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